# Isosceles Triangles

A triangle in which two of the sides are equal is called an “Isosceles triangle”, and we often identify the equal side by tagging them with a short line:

The third side is called the "base", and we will prove that the angels at the two sides of the base (and opposite the two equal sides) are congruent.

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*Now that we've explained the basic concept of isosceles triangles in geometry, let's scroll down to work on specific geometry problems relating to this topic.*